“My Name is Abdu’l-Bahá. My Reality is Abdu’l-Bahá: and Service to all the human race is my perpetual Religion…. Abdu’l-Bahá is the Banner of the Most Great Peace …The Herald of the Kingdom is he, so that he may awaken the people of the East and the West. The Voice of Friendship, of Truth, and of Reconciliation is he, quickening all regions. No name, no title will he ever have, except Abdu’l-Bahá. This is my longing. This is my Supreme height. O ye friends of God! Abdu’l-Bahá is the manifestation of Service, and not Christ. The Servant of humanity is he, and not a chief. Summon ye the people to the station of Service of Abdu’l-Bahá and not his Christhood.” ‘Abdu’l-Bahá (From ‘Abdu’l-Bahá in London, p. 109)

‘Abdu’l-Bahá often reminded his audience and followers of Bahá’u’lláh that His life was wholly devoted to the service of Bahá’u’lláh, and that their attention and service should directed toward Bahá’u’lláh and not Himself. He identified Himself exclusively as the Servant of Bahá. When Bahá’ís, during His ministry (1892 – 1921) continued to ask Him to create a Holy Day so that they might honor Him, he refused. Instead, He established the Day of the Covenant and set it on November 26th. Here is a comment about this from the historian and Hand of the Cause, H.M. Balyuzi:

” ‘Abdu’l-Bahá told the Bahá’ís that this day [the Declaration of the Báb, also ‘Abdu’l-Bahá’s birthday] was not, under any circumstances, to be celebrated as His day of birth. It was the day of the Declaration of the Báb, exclusively associated with Him. But as the Bahá’ís begged for a day to be celebrated as His, He gave them November 26th, to be observed as the day of the appointment of the Centre of the Covenant. It was known as Jashn-i-A’zam (The Greatest Festival), because He was Ghusn-i-A’zam — the Greatest Branch. In the West it is known as the Day of the Covenant.” (From H.M. Balyuzi, Abdu’l-Bahá – The Centre of the Covenant, p. 523)
The Covenant, and faithfulness to it, are of course essential for the mission of Bahá’u’lláh to succeed. The Faith must remain unified in order for its followers to accomplish their work. Following the passing of Bahá’u’lláh, ‘Abdu’l-Bahá, as Bahá’u’lláh’s appointed successor, became the Center of that Covenant, the source of that essential unity.

Remarkably (and was it more than a coincidence?) the date of ‘Abdu’l-Bahá’s own ascension is two days later, at 1:00 a.m. on November 28th.